<?php
/**
 * Class for working with MO files
 *
 * @version $Id: mo.php 718 2012-10-31 00:32:02Z nbachiyski $
 * @package pomo
 * @subpackage mo
 */

require_once dirname(__FILE__) . '/translations.php';
require_once dirname(__FILE__) . '/streams.php';

if (!class_exists('MO')):
    class MO extends Gettext_Translations
    {

        var $_nplurals = 2;

        /**
         * Fills up with the entries from MO file $filename
         *
         * @param string $filename MO file to load
         */
        function import_from_file($filename)
        {
            $reader = new POMO_FileReader($filename);
            if (!$reader->is_resource())
                return false;
            return $this->import_from_reader($reader);
        }

        function export_to_file($filename)
        {
            $fh = fopen($filename, 'wb');
            if (!$fh) return false;
            $res = $this->export_to_file_handle($fh);
            fclose($fh);
            return $res;
        }

        function export()
        {
            $tmp_fh = fopen("php://temp", 'r+');
            if (!$tmp_fh) return false;
            $this->export_to_file_handle($tmp_fh);
            rewind($tmp_fh);
            return stream_get_contents($tmp_fh);
        }

        function is_entry_good_for_export($entry)
        {
            if (empty($entry->translations)) {
                return false;
            }

            if (!array_filter($entry->translations)) {
                return false;
            }

            return true;
        }

        function export_to_file_handle($fh)
        {
            $entries = array_filter($this->entries, array($this, 'is_entry_good_for_export'));
            ksort($entries);
            $magic = 0x950412de;
            $revision = 0;
            $total = count($entries) + 1; // all the headers are one entry
            $originals_lenghts_addr = 28;
            $translations_lenghts_addr = $originals_lenghts_addr + 8 * $total;
            $size_of_hash = 0;
            $hash_addr = $translations_lenghts_addr + 8 * $total;
            $current_addr = $hash_addr;
            fwrite($fh, pack('V*', $magic, $revision, $total, $originals_lenghts_addr,
                $translations_lenghts_addr, $size_of_hash, $hash_addr));
            fseek($fh, $originals_lenghts_addr);

            // headers' msgid is an empty string
            fwrite($fh, pack('VV', 0, $current_addr));
            $current_addr++;
            $originals_table = chr(0);

            foreach ($entries as $entry) {
                $originals_table .= $this->export_original($entry) . chr(0);
                $length = strlen($this->export_original($entry));
                fwrite($fh, pack('VV', $length, $current_addr));
                $current_addr += $length + 1; // account for the NULL byte after
            }

            $exported_headers = $this->export_headers();
            fwrite($fh, pack('VV', strlen($exported_headers), $current_addr));
            $current_addr += strlen($exported_headers) + 1;
            $translations_table = $exported_headers . chr(0);

            foreach ($entries as $entry) {
                $translations_table .= $this->export_translations($entry) . chr(0);
                $length = strlen($this->export_translations($entry));
                fwrite($fh, pack('VV', $length, $current_addr));
                $current_addr += $length + 1;
            }

            fwrite($fh, $originals_table);
            fwrite($fh, $translations_table);
            return true;
        }

        function export_original($entry)
        {
            //TODO: warnings for control characters
            $exported = $entry->singular;
            if ($entry->is_plural) $exported .= chr(0) . $entry->plural;
            if (!is_null($entry->context)) $exported = $entry->context . chr(4) . $exported;
            return $exported;
        }

        function export_translations($entry)
        {
            //TODO: warnings for control characters
            return implode(chr(0), $entry->translations);
        }

        function export_headers()
        {
            $exported = '';
            foreach ($this->headers as $header => $value) {
                $exported .= "$header: $value\n";
            }
            return $exported;
        }

        function get_byteorder($magic)
        {
            // The magic is 0x950412de

            // bug in PHP 5.0.2, see https://savannah.nongnu.org/bugs/?func=detailitem&item_id=10565
            $magic_little = (int)-1794895138;
            $magic_little_64 = (int)2500072158;
            // 0xde120495
            $magic_big = ((int)-569244523) & 0xFFFFFFFF;
            if ($magic_little == $magic || $magic_little_64 == $magic) {
                return 'little';
            } else if ($magic_big == $magic) {
                return 'big';
            } else {
                return false;
            }
        }

        function import_from_reader($reader)
        {
            $endian_string = MO::get_byteorder($reader->readint32());
            if (false === $endian_string) {
                return false;
            }
            $reader->setEndian($endian_string);

            $endian = ('big' == $endian_string) ? 'N' : 'V';

            $header = $reader->read(24);
            if ($reader->strlen($header) != 24)
                return false;

            // parse header
            $header = unpack("{$endian}revision/{$endian}total/{$endian}originals_lenghts_addr/{$endian}translations_lenghts_addr/{$endian}hash_length/{$endian}hash_addr", $header);
            if (!is_array($header))
                return false;

            extract($header);

            // support revision 0 of MO format specs, only
            if ($revision != 0)
                return false;

            // seek to data blocks
            $reader->seekto($originals_lenghts_addr);

            // read originals' indices
            $originals_lengths_length = $translations_lenghts_addr - $originals_lenghts_addr;
            if ($originals_lengths_length != $total * 8)
                return false;

            $originals = $reader->read($originals_lengths_length);
            if ($reader->strlen($originals) != $originals_lengths_length)
                return false;

            // read translations' indices
            $translations_lenghts_length = $hash_addr - $translations_lenghts_addr;
            if ($translations_lenghts_length != $total * 8)
                return false;

            $translations = $reader->read($translations_lenghts_length);
            if ($reader->strlen($translations) != $translations_lenghts_length)
                return false;

            // transform raw data into set of indices
            $originals = $reader->str_split($originals, 8);
            $translations = $reader->str_split($translations, 8);

            // skip hash table
            $strings_addr = $hash_addr + $hash_length * 4;

            $reader->seekto($strings_addr);

            $strings = $reader->read_all();
            $reader->close();

            for ($i = 0; $i < $total; $i++) {
                $o = unpack("{$endian}length/{$endian}pos", $originals[$i]);
                $t = unpack("{$endian}length/{$endian}pos", $translations[$i]);
                if (!$o || !$t) return false;

                // adjust offset due to reading strings to separate space before
                $o['pos'] -= $strings_addr;
                $t['pos'] -= $strings_addr;

                $original = $reader->substr($strings, $o['pos'], $o['length']);
                $translation = $reader->substr($strings, $t['pos'], $t['length']);

                if ('' === $original) {
                    $this->set_headers($this->make_headers($translation));
                } else {
                    $entry = & $this->make_entry($original, $translation);
                    $this->entries[$entry->key()] = & $entry;
                }
            }
            return true;
        }

        /**
         * Build a Translation_Entry from original string and translation strings,
         * found in a MO file
         *
         * @static
         * @param string $original original string to translate from MO file. Might contain
         *    0x04 as context separator or 0x00 as singular/plural separator
         * @param string $translation translation string from MO file. Might contain
         *    0x00 as a plural translations separator
         */
        function &make_entry($original, $translation)
        {
            $entry = new Translation_Entry();
            // look for context
            $parts = explode(chr(4), $original);
            if (isset($parts[1])) {
                $original = $parts[1];
                $entry->context = $parts[0];
            }
            // look for plural original
            $parts = explode(chr(0), $original);
            $entry->singular = $parts[0];
            if (isset($parts[1])) {
                $entry->is_plural = true;
                $entry->plural = $parts[1];
            }
            // plural translations are also separated by \0
            $entry->translations = explode(chr(0), $translation);
            return $entry;
        }

        function select_plural_form($count)
        {
            return $this->gettext_select_plural_form($count);
        }

        function get_plural_forms_count()
        {
            return $this->_nplurals;
        }
    }
endif;